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  • 1
    Electronic Resource
    Electronic Resource
    Structural analysis of poly(4-hydroxybutyl acrylate)-grafted silk fibres (1996)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 241 (1996), S. 41-56 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Poly(4-hydroxybutylacrylat) poly(4-HBA) wurde aus wäßrigem Medium mit Ammoniumpersulfat als Initiator auf Seide (bombyx mori) aufgepfropft. Die Gewichtszunahme stieg proportional mit der Monomerkonzentration im Pfropfsystem. Der Pfropfgrad lag im Bereich von 45 bis 65%. Die Feuchtigkeitsaufnahme nahm bei einer Gewichtszunahme von 〉10% stark ab. Die mechanischen Eigenschaften der Seidenfasern zeigten mit steigender Gewichtszunahme keine wesentliche Änderung. Doppelbrechung und isotroper Brechungsindex nahmen bis zu einer Gewichtszunahme von 35% ab und blieben dann unverändert. Röntgenbeugungsdiagramme zeigten, daß die kristalline Struktur durch die Pfropfbehandlung nicht modifiziert wird. Kalorimetrische (DSC), thermomechanische (TMA) und thermogravimetrische (TG) Analysen ergaben, daß das thermische Verhalten der poly(4-HBA)-gepfropften Seidenfasern nur leicht verändert wird. Die zur Bestimmung des dynamisch-mechanischen Verhaltens der Seidenfasern durchgeführten DMA-Messungen zeigten eine Verschiebung der E′- und E″-Modulspitzen zu niedrigeren Temperaturen mit steigender Gewichtszunahme. Ablagerungen auf der Faseroberfläche der bei einem hohen Monomer/Seide-Verhältnis (〉50%) gepfropften Seide wurden mit Rasterelektronenmikroskopie nachgewiesen.
    Notes: Poly(4-hydroxybutyl acrylate) poly(4-HBA) was graft-copolymerized onto silk fibres (bombyx mori) in aqueous medium with ammonium persulfate as initiator. The weight gain increased with increasing concentration of monomer in the grafting system. The grafting efficiency ranged from 45 to 65%. Equilibrium moisture regain decreased sharply beyond 10% weight gain. The tensile properties of the silk fibres did not change significantly as a function of the increasing weight gain. Birefringence and isotropic refractive index decreased until 35% weight gain and then remained unchanged. The X-ray diffraction patterns showed that the crystalline structure was not affected by grafting. Differential scanning calorimetry (DSC), thermomechanical (TMA), and thermogravimetric (TG) measurements showed that poly(4-HBA)-grafted silk fibres underwent only slight changes in the thermal behaviour. The dynamic mechanical measurements (DMA) exhibited a downward shift of both the storage (E′) and loss modulus peak (E″) with increasing weight gain. Scanning electron microscopy (SEM) observations showed the presence of some deposits adhering to the surface of silk fibres grafted at high monomer/silk ratio (〉50%).
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1996.052410104
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  • 2
    Electronic Resource
    Electronic Resource
    Formation of α nylon 12 by drawing (1979)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 180 (1979), S. 2999-3001 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1979.021801224
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  • 3
    Electronic Resource
    Electronic Resource
    The molecular structures of (RS)-1,2-diphenylethyl methacrylate and (RS)-α-tert-butylbenzyl methacrylate (1984)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 185 (1984), S. 913-932 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The molecular structures of (RS)-1,2-diphenylethyl methacrylate (DPEMA) and (RS)-α-tert-butylbenzyl methacrylate (t-BBMA) were determined by means of X-ray diffraction. Crystals of (RS)-DPEMA are monoclinic, space group C2/c, a = 33,341(3), b = 5,916(1), c = 15,911(2) Å, β = 106,42(1)°, and Z = 8. Crystals of (RS)-t-BBMA are also monoclinic, space group P21/c, a = 6,028(1), b = 31,009(3), c = 15,207(1) Å, β = 96,780(8)°, and Z = 8. Both structures were solved by the direct method and refined by the block-diagonal least-squares procedure: DPEMA, R = 0,113 for 1 100 observed reflections and t-BBMA, R = 0,081 for 2206 non-zero reflections, respectively. The molecule of DPEMA has an antiperiplanar conformation as to the C=C and C=O double bonds about the C(1)—C(2) bond, a synperiplanar conformation as to the C=O and C—O bond about the C(1)—O(1) bond, and an anticlinal conformation about the O(1)—C(5) bond. One of the two t-BBMA molecules in an asymmetric unit has an antiperiplanar conformation as to the C=C and C=O double bonds about the C(1)—C(2) bond, whereas the other antiperiplanar molecule may contain some synperiplanar conformation. Both molecules have a synperiplanar conformation as to the C=O and C—O bonds about the C(1)—O(1) bond and an anticlinal conformation about the O(1)—C(5).
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1984.021850508
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  • 4
    Electronic Resource
    Electronic Resource
    The molecular structures of methacrylates with bulky ester substituents, (RS)-1,2,2,2-tetraphenylethyl methacrylate and (1S, 2R)-(+)-1-benzyl-3-dimethylamino-2-methyl-1-phenylpropyl methacrylate (1984)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 185 (1984), S. 933-955 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The molecular structures of (RS)-1,2,2,2-tetraphenylethyl methacrylate (TrBzMA) and (1S, 2R)-(+)-1-benzyl-3-dimethylamino-2-methyl-1-phenylpropyl methacrylate (ChMA) were determined by means of X-ray diffraction: (RS)-TrBzMA .0,5C6H6; triclinic, space group P1, a = 9,271(2), b = 33,965(4), c = 9,167(2) Å, α = 90,26(2), β = 118,80(2), γ = 88,03(2)°, and Z = 4; ChMA; monoclinic, space group P21, a = 12,482(1), b = 9,184(1), c = 9,246(1) Å, β = 93,49(1)°, and Z = 2. Both structures were solved by the direct method and refined by the block-diagonal least-squares procedure to R = 0,054 and 0,057 for non-zero reflections, respectively. Both of the two crystallographically independent molecules of TrBzMA have the same structure; each molecule has a synperiplanar (sp) conformation as to the C=C and C=O double bonds about the C(1)—C(2) bond and also an sp conformation as to the C=O and C—O bonds about the C(1)—O(1) bond. The ChMA molecule has an antiperiplanar (ap) and a sp conformation about the C(1)—C(2) and C(1)—O(1) bonds, respectively.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1984.021850509
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  • 5
    Electronic Resource
    Electronic Resource
    The γ → α partial transformation in nylon 12 by drawing (1981)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 182 (1981), S. 977-988 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Partial development of the α form crystals in γ nylon 12 has been found to take place by drawing near the melting point. The confirmation of the α form has been made by X-ray diffraction, infrared absorption, and differential scanning calorimetry. The amount of the α form varies depending upon the temperature of drawing and draw ratio, whereas it is almost independent of the rate of drawing. The minimum draw ratio necessary to yield the α form increases as the temperature of drawing decreases. The crystallinity, determined from the density, also increases with the increase in the temperature of drawing and draw ratio, while it decreases slightly with the increase in the rate of drawing. The development of the α form is ascribable to the transformation from the γ form rather than the crystallization from the amorphous region. The total figure of the polymorphism in nylon 12 is proposed.
    Additional Material: 15 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1981.021820328
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  • 6
    Electronic Resource
    Electronic Resource
    The molecular structures of 1,1-diphenylethyl methacrylate and triphenylmethyl methacrylate (1985)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 186 (1985), S. 203-214 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The molecular structures of 1,1-diphenylethyl methacrylate (1,1-DPEMA) and triphenylmethyl methacrylate (TrMA) were determined by means of X-ray diffraction. 1,1-DPEMA: monoclinic, space group P21/a,a = 9,666(6), b = 19,94(2), c = 8,132(6) Å, β = 104,49(7)°, and Z = 4; TrMA: monoclinic, space group P21/n, a = 17,349(3), b = 9,487(2), c = 11,254(2) Å, β = 102,30(2)°, and Z = 4. Both structures were solved by the direct method and refined by the block-diagonal least-squares procedure to R = 0,175 and 0,056 for non-zero reflections, respectively. In both molecules, conformations about the C(1)—C(2) and C(1)—O(1) bonds are all synperiplanar and one of the two or three phenyl groups attached to the C(5) atom is in trans to the O(2).
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1985.021860119
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  • 7
    Electronic Resource
    Electronic Resource
    The molecular structure of diphenylmethyl methacrylate (1982)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 183 (1982), S. 2863-2870 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The molecular structure of diphenylmethyl methacrylate has been determined by means of X-ray diffraction. Crystals are monoclinic, space group C2/c, a = 29, 177 (2), b = 6,017(1), c = 16,110(1) Å, β = 96,840(5)°, and Z = 8. The structure was solved by the direct method and refined by the block-diagonal least-squares procedure to R = 0,071 (Rw = 0,091) for 1768 measured reflections. The molecule has an antiperiplanar conformation as to the C=C and C=O double bonds about the C(1)—C(2) bond and a synperiplanar conformation as to the C=O and C—O bonds about C(1)—O(1).
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1982.021831121
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  • 8
    Electronic Resource
    Electronic Resource
    X-ray studies on diethynylbenzene derivatives in view of the solid-state polymerization (1987)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 188 (1987), S. 3047-3059 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The crystal structures of three diethynylbenzene derivatives, 3-[2-(3-acetoxy-1-propynyl)-4,5-dimethylphenyl]-2-propynyl acetate (1a), 3-[4-(3-acetoxy-1-propynyl)-2,5-dimethylphenyl]-2-propynyl acetate (1b), and 3-[2-(3-acetoxy-1-propynyl)-4,5-dimethoxyphenyl]-2-propynyl acetate (2), were determined by means of X-ray diffraction. The unique monomer packings interpret the characteristic freatures of these compounds in the solid-state polymerization upon irradiation with γ rays.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1987.021881225
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  • 9
    Electronic Resource
    Electronic Resource
    Structure and molecular conformation of tussah silk fibroin films: Effect of methanol (1995)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part B: Polymer Physics 33 (1995), S. 1995-2001 
    Details
    ISSN: 0887-6266
    Keywords: tussah silk fibroin ; methanol treatment ; molecular conformation ; crystallization ; Raman spectroscopy analysis ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Structural changes of tussah (Antheraea pernyi) silk fibroin films treated with different water-methanol solutions at 20°C were studied as a function of methanol concentration and immersion time. X-ray diffraction measurements showed that the α-helix structure, typical of untreated tussah films, did not change for short immersion times (2 min), regardless of methanol concentration. However, crystallization to β-sheet structure was observed following immersion of tussah films for 30 min in methanol solutions ranging from 20 to 60% (v/v). IR spectra of tussah films untreated and methanol treated for 2 min exhibited strong absorption bands at 1265, 892, and 622 cm-1, typical of the α-helix conformation. The intensity of the bands assigned to the β-sheet conformation (1245, 965, and 698 cm-1) increased for the sample treated with 40% methanol for 30 min. Raman spectra of tussah films with α-helix molecular conformation exhibited strong bands at 1657 (amide I), 1263 (amide III), 1106, 908, 530, and 376 cm-1. Following α → β conformational transition, amide I and III bands shifted to 1668, and to 1241, 1230 cm-1, respectively. The band at 1106 cm-1 disappeared and new bands appeared at 1095 and 1073 cm-1, whereas the intensity of the bands at 530 and 376 cm-1 decreased significantly. ©1995 John Wiley & Sons, Inc.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/polb.1995.090331402
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  • 10
    Electronic Resource
    Electronic Resource
    Structural changes of silk fibroin membranes induced by immersion in methanol aqueous solutions (1994)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part B: Polymer Physics 32 (1994), S. 961-968 
    Details
    ISSN: 0887-6266
    Keywords: silk fibroin ; β structure ; crystallization ; molecular conformation ; glass transition ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Structural changes of native and regenerated silk fibroin membranes were induced by immersion in water-methanol solutions and examined as a function of immersion time and methanol concentration. X-ray diffractometry and infrared spectroscopy data showed that transition from random coil to β-sheet structure occurred favorably when both native and regenerated silk fibroin membranes were immersed in water-methanol solutions, regardless of the different immersion time. Only native silk membrane, treated for 2 min with pure methanol, maintained its original amorphous structure, as demonstrated by differential scanning calorimetric (DSC) curves. The degree of displacement, measured by thermomechanical analysis (TMA), was much greater for regenerated than for native silk fibroin membranes. SDS-PAGE pattern showed that native silk fibroin has a molecular weight of 350, while the regenerated sample is formed by a large number of polypeptides in the range of 200-50 KD. The amount of acidic and basic amino acids decreased slightly in regenerated silk fibroin. Physical properties of silk membranes treated with water-methanol solutions are discussed in terms of membrane structure, treatment conditions, and chemical structure of starting material. © 1994 John Wiley & Sons, Inc.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/polb.1994.090320519
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